There are concerns over the number of workers who may have access to the database

Up to a million public sector workers could be allowed to access a Government database containing sensitive information on every child in England and Wales, it has emerged.

Critics say the figure is three times higher than ministers told Parliament, and raises further privacy concerns about the controversial ContactPoint system.

The database will contain the name, home address and school of all 11million children. It will also include information about their legal guardians.

It is designed to make it easier for public bodies to share information. Those permitted by law to access it include bureaucrats such as school ‘administrators’ and ‘any employee’ of a police force.

But campaigners fear that the greater the number of users, the more chance the database will be trawled by the likes of abusive former partners seeking a reunion.

Phil Booth, of the NO2ID privacy campaign, said: ‘Rather than the 330,000 they have previously suggested – which was bad enough – it appears that a million or more people will be able to get access under the terms of the Children Act.

‘This, in the light of the Government’s own auditors saying that ContactPoint could never be made secure, paints a deeply disturbing picture.’

Maria Miller, Conservative spokesman for children, schools and families said: ‘They have grossly underestimated the number of people who will have access to children’s data and now more children will be put at risk. ContactPoint should be scrapped.’

And Baroness Sue Miller, a Liberal Democrat peer with a special interest in data protection issues, said: ‘The ContactPoint system was dubious to start with. It would have been irrelevant to key cases such as that of Victoria Climbie. This latest revelation merely makes it at least three times worse.’

Lord Adonis and Kevin Brennan, ministers for the Department for Children, Schools and Families, have told both houses of Parliament that ‘the number of users (of ContactPoint) is estimated to be around 330,000’.

But the legislation governing the database lists a huge number who could potentially be granted access.

These range from senior police officers and headmasters to officers of local probation area boards and administrators working in schools or further education colleges.

Publicly available staffing figures from education authorities, the NHS, social services and other organisations show that the number of those falling into the categories listed by the Government is one million, according to the respected technology news website Register .

The system, which is the centrepiece of the Government’s Every Child Matters strategy, has been shrouded in controversy since it was first announced, and has been delayed twice.

Both the Conservatives and the Liberal Democrats have pledged to scrap ContactPoint.

The Tories want to replace it with a smaller system that will only hold data on children deemed at risk.

Whitehall officials wrote to councils in October arguing against the alternative scheme.

The DCSF later apologised for the breach of civil service political impartiality rules.

A spokesman for the department said: ‘Access to ContactPoint will be strictly limited to those who need it as part of their work and subject to stringent security controls. Not everyone who works in one of the roles listed in the regulations will be permitted access.

‘We have consistently maintained that the estimated number of users for ContactPoint is around 330,000, and this takes into account those needing access across all relevant sectors. This number was informed by the experience of trailblazers, who developed their own systems locally.’